1. Field of the Invention
This invention relates to the packaging of storage and/or server equipment, and more particularly a low profile tray for multi-disk storage or server systems and an enclosure for such trays.
2. Description of the Related Art
One problem facing many office computing environments is how to physically arrange and store office computing equipment in a limited amount of space. Typically, an office may have a central computing room in which most of the office server systems are located. Naturally, it is desirable for such computer rooms to require as little real estate as possible. Conventional server systems are often packaged in tower type chassis that are often not very space efficient. Such chassis are typically not stackable and may require a large amount of clearance for fan airflow, etc. Some computer environments employ racks to mount computer systems in a more space efficient manner. A standard-industrial 19 inch rack is often used. The current 19 inch industrial rack accommodates equipment trays in height units of 1.75 inches. Multiple trays may be stacked up in a single rack. However, an office may not be able to readily obtain all of its server needs in this form factor, or at the very least, its choice for file servers, email servers, web servers, network servers, etc., may be restricted if they are limited to this form factor. Furthermore, with the increasing miniaturization of components, the 1.75 inch height unit of the current industrial standard racks may be an inefficient use of space. Therefore, a more compact solution to support the physical installation of server systems may be desirable.
A ribbed tray or substrate may be provided for holding computer or storage system components. The total height of the tray and components may be less than or equal to one inch. A number of such trays may be stacked inside of a cage which may be mounted inside a standard 19 inch computer rack. Such a cage may be designed to accommodate the one inch trays or larger 1.75 inch (height) trays. Each tray may be based on a printed circuit board reinforced with metal ribs in at least one direction and preferably in both an x and y direction. A tray may be populated with low profile components so that the height of the tray including the printed circuit board thickness, ribs, components, and any necessary clearance is less than or equal to one inch. The structural ribs may be oriented to allow front to back airflow and the trays may be configured to slide into the cage independently of one another.
An edge connector at the rear of the tray printed circuit board provides connectivity between trays in the cage and to a power supply and external ports, such as a network port. In one embodiment, to maximize useful space, trays are not individually packaged inside their own metal case.
The tray may be mounted into the cage in much the same fashion as in a bakery rack. Slots may be grooved out, or rails provided in the internal sidewalls of the cages to accommodate the tray substrate. Each tray slides into the cage from the front and connects to a back plane at the rear of the cage via the printed circuit board edge connector. For a high degree of compatibility the back plane may provide a standard interconnect, such as a point to point switched interconnect (e.g., as proposed by the Infiniband Trade Association) or the PCI bus or high bandwidth variant of the PCI bus.
The ribs on each tray provide enough strength such that the tray does not collapse under its own weight. Also, to avoid sagging in the middle section, heavier components may be distributed such that most of the weight is located near ribs or near sides that slide into the cage. Also, the ribs may be designed so that vertically adjacent trays have their ribs rest on top of one another to provide additional support. Dummy trays may be inserted to maintain the support if a regular tray is removed or uninstalled.
The trays may be powered by a Telco-standard 48 volt DC supply. Local regulation may further be done on each tray to convert 48V DC to the voltages required by the equipment on the tray using xe2x80x9cbrickxe2x80x9d or xe2x80x9chalf-brickxe2x80x9d form factor integrated power supply modules having a low profile. The cage back plane may provide redundant power supply tracks so that multiple power supply trays, or independent supplies on the same tray, may be used for better fault tolerance. Cooling may be provided by a set of fans at the back of the cage. To facilitate front to back airflow, the cage back plane may be perforated or otherwise appropriately shaped. In one embodiment, a row of smaller fans may be included across each tray.
In one embodiment, a tray includes two ribs along the y axis which delineate the tray into multiple regions. A plurality of disk drives may be mounted in two of these regions. Power supplies and control circuitry may be located in another region. In a preferred embodiment, at least one additional rib exists along the x axis to further divide the tray. The power supply may be located on one side of this rib, and the control circuitry including one or more drive array controllers and one or more CPU""s may be located on the other side of the rib. This transverse rib may also be perforated or a low height rib to facilitate front to back airflow. In one embodiment, the ribs are metal ribs and may serve as electromagnetic barriers and/or heat sinks for the power supplies. A memory backup battery may be included in the power supply section as well.
One embodiment of the cage may be configured to hold three, one inch height trays or two 1.75 inch trays. The one inch height trays may include a plurality of low profile hard drives, such as hard drives designed for laptop computers. In one embodiment, each tray may be populated with 16 such drives so that a three tray cage may include 48 low profile drives. For 25 gigabyte drives, the cage would provide 1.2 terabytes of storage. In one embodiment this may be configured to provide one terabyte of storage plus 200 gigabytes of hot spare storage. In alternate designs, larger desktop type disk drives may be used with 1.75 inch height trays. The same tray substrate design may be employed with each larger drive occupying the space allotted for two of the smaller drives. This alternate design requires no change to the printed circuit board substrate except for the possible addition of a flexible cable that connects the larger drives to the substrate connector for the smaller drives.
Thus, a substrate for packaging a storage or server system may include one or more sections of the substrate configured to hold a two-dimensional array of disk drives. Another section of this substrate may be configured to hold circuitry for accessing the array of disk drives. This circuitry may include one or more processors. The substrate also includes a first plurality of ribs positioned in the first access of the substrate. The first plurality of ribs separate the sections from one another. The section configured to hold the control circuitry may also be configured to hold one or more power supplies for supplying power to the array of disk drives and control circuitry. This section, as well as other sections, may be divided in two by one or more additional ribs in a transverse direction.
The substrate may be configured to be mounted in a cage or rack and may include an edge connector at one edge of the substrate to provide electrical connectivity to a back plane in the cage or rack. A lateral protrusion may extend along each parallel edge of the substrate for mounting the substrate in the cage or rack by sliding the substrate into the cage or rack.
A storage or computing system may be provided including a two-dimensional array of disk drives mounted to a substrate. The two-dimensional array of disk drives may extend across the substrate along a first axis and second axis. Circuitry for controlling the two-dimensional array disk drives may also be included. This circuit may be mounted to the substrate and may include one or more processors. A first plurality of ribs may be positioned in the direction of the first axis separating the two-dimensional array of disk drives from the circuitry. A second plurality of ribs may be positioned in the direction of a second axis of the substrate perpendicular to the first axis. These ribs may be perforated or low profile ribs to facilitate airflow in the direction of the first axis.
A cage mounted storage or computing system may include a cage having a plurality of slots and a plurality of trays each mounted in one of the slots. Each tray may include a two-dimensional array disk drives mounted to a substrate. The two dimensional array disk drives may extend across the substrate along a first axis and a second axis of the substrate. Circuitry for controlling the two-dimensional array of disk drives may be mounted on the substrate and may include one or more processors. The plurality of trays may be mounted in the cage in a vertical stack. Each of the trays may include a first plurality of ribs positioned in the direction of a horizontal first axis. These ribs may be configured to rest upon corresponding top portions of ribs for an immediately lower tray. One of the trays may be a dummy tray configured to provide mechanical support via the ribs. A back plane may be provided at the back of a cage configured to provide power and I/O signals to each tray. The back plane may provide redundant power paths and may provide connections to I/O ports, such as network ports and may include an I/O interconnect fabric. One or more fans may be included at the rear of the cage. Additionally, each tray may be configured as an independent field replaceable unit with no field serviceable internal parts. Thus, if a tray fails, instead of field servicing its internal components, the entire tray is replaced as a whole.